Datasheet

Copyright © 2010 Future Technology Devices International Limited 26
Document No.: FT_000052
FT245R USB FIFO IC Datasheet Version 2.12
Clearance No.: FTDI# 39
8 Application Examples
The following sections illustrate possible applications of the FT245R. The illustrations have omitted pin
numbers for ease of understanding since the pins differ between the FT245RL and FT245RQ package
options.
8.1 USB to MCU FIFO Interface
FT245R
A
G
N
D
G
N
D
G
N
D
G
N
D
T
E
S
T
100nF
3V3OUT
VCCIO
NC
RESET#
NC
+
100nF
4.7uF
Vcc
D0
D1
D2
D3
D4
D5
D6
D7
RXF#
WR#
RD#
TXE#
USBDP
USBDM
VCC
1
2
3
4
5
OSCI
OSCO
PWREN#
Microcontroller
I/O10
I/O11
I/O12
I/O13
Ferrite
Bead
GND
GND
GND
+
GND
10nF
VCC
I/O14
I/O15
I/O16
I/O17
I/O20
I/O21
I/O22
I/O23
I/O24
Vcc
10k
SHIELD
VCC
Figure 8.1 USB to MCU FIFO Interface
A typical example of using the FT245R as a USB to Microcontroller (MCU) FIFO interface is illustrated in
Figure 8.1. This example uses two MCU I/O ports: one port (8 bits) to transfer data and the other port (4
or 5 bits) to monitor the TXE# and RXF# status bits and generate the RD# and WR strobes to the
FT245R, when required.
Using PWREN# for this function is optional.
If the Remote Wakeup option is enabled in the internal EEPROM, during USB suspend mode RXF#
becomes an input which can be used to wake up the USB host controller by strobing the pin low.